Two-cycle engine



Nov. 19, 1935. c. E. FREDER| CKSON TWO- CYCLE ENGINE I Filed Oct. 29, 1954 CEFfederic/(son WQwaM/L Sfromw Patented Nov. 19, 1935 UNITED STATES PATENT OFFICE 16 Claims.

My invention, which relates in general to the art of internal combustion engines, particularly has for an object to provide a simple, effective, efficient and inexpensive safe. engine for use on motor bicycles, or so-called motor-cycles.

Another object is to provide an engine with an adequate air cooling system in virtue of which the lubricating oil will be prevented from being vaporized and blown out through the exhaust by the hot gases and thereby wasted.

Further, it is an object to provide a two-cycle internal combustion engine with a cup-piston that telescopes with a cupped cylinder head, the walls of the cylinder head and the cylinder being cooled, preferably by radiator fins.

Again, it is an object to provide an engine of the type referred to above in which no exploded gases are exposed to the cooled walls, thereby keeping the gases expanded until the power stroke is completed and the exhaust port opened.

Still further, it is an object of the invention to provide an engine whose crank case serves as the mixing and initial-compression chamber in which chamber is located the fly-wheels so as to reduce the volume of the chamber to a minimum and obtain an initial high compression of the mixture so that when the inlet port to the explosion chamber opens enough mixture will be by-passed to fill the explosion chamber.

Again, it is an object to provide an engine whose piston is in the form of a cup having a sleeve to telescope with a cupped cylinder head that is provided with a dome at the bottom which serves as a compression chamber or space and also serves to carry the spark plug; an engine whose piston is also provided with a dome to enter the compression space and thereby reduce its volume to a minimum and compress the charge within the compression space to as high a degree as possible.

Other objects will in part be obvious and in part be pointed out hereinafter.

To the attainment of the aforesaid objects and ends, the invention still further resides in those novel details of construction, combination and arrangement of parts, all of which will be first fully described in the following detailed descripticn, then be pointed out in the appended claims, ref erence being had to the accompanying drawing in which: V

Figure 1 is a vertical longitudinal section of a single cylinder engine embodying my invention.

Figure 2 is a. view of the cylinder head end thereof, looking in the direction of the arrow in Figure l.

In the drawing, in which like numerals of reference indicate like parts in all the figures, l represents the crank case which has suitable bearings in which the crank shaft 2 is mounted and in which the fly-wheels 3, on the crank shaft, are 6 located.

4 indicates the crank to which one end of the connecting rod 44 is pivoted, the other end of the rod being pivoted to the wrist pin 43 hereinafter again referred to. 10

The crank case is preferably provided with a suitable boss 5 on which is mounted the usual magneto 6, whose shaft I is driven through a gear train I, 8 and 9 from the crank shaft 2.

The crank case I is also provided with a boss 16 ll having an opening over which is secured the gas-valve cage l2 and the gas-pipe union IT. The gas valve l3, whose stem It operates a hearing in the cage l2, carries a closing spring l and tension adjusting nut IS. The cylinder I8 20 extends from the crank case I and is provided with a gas port it adJacent the crank case, which port communicates through a by-pass duct 2| with the fuel admission port 20 in the wall of the cylinder it. The by-pass duct 2| has an opening 22 over which is mounted the air valve cage 23 in a bearing in which operates the stem 25 of the air valve 24, there being a closing spring 26 and a tension adjusting nut 21 provided for the usual purpose. to

The cylinder I8 is provided with cooling fins 28 arranged in horizontal planes, it being understood that the axis of the cylinder 18 is inclined to the horizontal.

The cylinder, at its outer end, has a flange 29 to cooperate with the flange 3| of the cylinder head, the flanges being securedv together by means of cap screws 32, the usual gasket 48 being provided to effect a gas-tight joint. The cylinder head includes the sleeve 30 which projects into the cylinder l8 and is spaced from the wall thereof a distance sufficient to provide a space for the reception of the sleeve 40 of the cup piston. At its bottom or inner end the cylinder head is provided with a dome 33 which encloses the compression space for the working charge of fuel. The dome 33 is bored and tapped at 35 to receive the usual spark plug 38,. A suitable packing ring 34 is provided to effect a gas-tight engagement between the inner surface oi the sleeve 40 of the piston and the sleeve 30 of the cylinder head. The cylinder head is also provided with a deflecting lip 36 that is located adjacent to and in line with the port 20. Suitable cooling fins 31 are provided on the cylinder head. These fins may extend only across the top fiange 3| or they may be extended down into the sleeve 36 as indicated in the drawing, the latter being preferable.

The cylinder I3 is provided with an exhaust port 39, preferably located opposite the inlet port 26, and the sleeve 40 of the cup piston is provided with an inlet port 45 and an outlet or exhaust port 46, these ports 45 and 46 lining up respecforming bearings for the wrist pin 43,hereinbefore mentioned. By properly adjusting the tension of the springs I5 and 26 the desired mixture of air and gas is obtained.

In operation when the piston is traveling inwardly on the working stroke, the gaseous fluid within the crank case i and by-pass duct 2! is being compressed. It will be noted that the exhaust port 46 begins registering with the exhaust port 39 before the port 45 begins to register with the port 26, thereby opening the exhaust before opening the inlet, thus allowing the pressure within the piston to be reduced before a new charge is blown into the working chamber (contained within the cup-piston) and blowing out the burnt mixtureand filling the cup-piston anddome 33 with a fresh charge.

Assume the. piston to the position shown in Q Figure 1: as it moves upwardly or toward the outer end of the cylinder, the ports and 46 will leave the ports 26 and 36 respectively, thereby closing the inlet and exhaust ports and effecting acompression of the mixture within 'the cuppiston and dome 33, and at the same time sucking into the crank case a fresh supply of fuel via gas valve l3 and air via valve 24. When the piston has reached the outer limit of its stroke the charge in the compression space 33 will be fired by the spark plug and the piston impelled on its working stroke, thereby compressing the new cylinder and having a sleeve to be received into charge of gaseous mixture within the crank case I and by-pass 2i until the ports 26 and 45 are again in register, thus completing the cycle of operation.

Lubricating oil may be fed in with the gasoline. As the wall of the cylinder l6 and the wall 36 of the cylinder head are kept cool by the radiator fins 26 and 31 respectively, excessive vaporization of the lubricating oil, which lubricates the moving surfaces of the piston, is prevented and very little of the lubricating oil is therefore blown out with the expended mixture.

From the .foregoing description, taken in connection with the accompanying, drawing, it is thought that the complete construction, operationand advantages of my invention will be clear to those skilled in the art.

'Whatfclaim is:

1. In a two-cycle crank case compression type of internal combustion engine, a cylinder, a cupped head projecting into the cylinder and spaced from the wall thereof, a cup-piston located within the the space between the cylinderhead and the cylis I inder wall, a crank case, a crank shaft mounted in the case, a connecting rod between said crank shaft and said piston, said cylinder and said pistons sleeve having mixture inlet ports and exhaust outlet ports controlled by the position of the piston, a by-pass duct from the crank case to said inlet ports, means to admit fuel and air into said crank case on the outer stroke of said piston, and means to effect. ignition of the working mixture within the piston at the proper time, said cylinder head being cupped and having a dome projecting into the cup to enclose a compression chamber and having a portion to receive a spark 10 plug.

2. In a two-cycle crank case compression type of internal combustion engine, a cylinder, a cupped head projecting into the cylinder and spaced from the wall thereof, a cup-piston located within the 15 cylinder and having a sleeve to be received into the space between the cylinder head and the cylinder wall, a crank case, a crank shaft mounted in the case, a connecting rod between said crank shaft and said piston, said cylinder and said pis- 20 tons sleeve having mixture inlet ports and exhaust outlet ports controlled by the position of the piston, a by-pass duct from the crank case to said inlet ports, means to admit fuel and air into said crank case on the outer stroke of said piston, 2.3 and means to effect ignition of the working mixture within the piston at the proper time, said cylinder head being cupped and having a dome projecting into the cup to enclose a compression chamber and having a portion to receive a spark 3') plug, said cylinder head having a deflecting lip located opposite and adjacent the inlet port of the cylinder.

3. In a two-cycle crank case compression type of internal combustion engine, a cylinder, is cupped 35 head projecting into the cylinder and spaced from the wall thereof, a cup-piston located within the cylinder and having a sleeve to be received into the space between the cylinder head and the cylinder wall, a crank case, a crank shaft mounted .y in the case, a connecting rod between said crank shaft and said piston, said cylinder and said pistons sleeve having mixture inlet ports and exhaust outlet ports controlled by the position of the piston, a by-pass duct from the crank case to said inlet ports, means to admit fuel and air into said crank case on the outer stroke of said piston, and means to effect ignition of the working mixture within the piston at the proper time, said cylinder head being cupped and having a dome pro jecting into the cup to enclose a compression chamber and having a portion to receive a spark plug, said piston having a dome to cooperate with the dome of the cylinder head for the purposes specified.

4. In a two-cycle crank case compression type of internal combustion engine, a cylinder, a cupped head projecting into the cylinder and spaced from the wall thereof, a cup-piston located within the cylinder and having a sleeve to be received into C the space between the cylinder head and the cylinder wall, a crank case, a crank shaft mounted in the case, a connecting rod between said crank shaft and said piston, said cylinder and said pis-, ton's' sleeve having mixture inlet ports and exhaust g 3 outlet ports controlled by the position of the piston, a by-pass duct from the crank case to said inlet ports, means to admit fuel and air into said crank case on the outer stroke of said piston, and means to effect ignition of the working mixture within the piston at the proper time, said cylinder head being'cupped and having a dome projecting into the cup to enclose a compression chamber and having a portion to receive a spark a plug, said cylinder head having a deflecting lip located opposite and adjacent the inlet port of the cylinder, said piston having a dome to cooperate with the dome of the cylinder head for the purposes specified.

5. In a two-cycle internal combustion engine, a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having a fuel inlet port to the working chamber and a bypass duct between the crank case and said port, said cylinder having an exhaust port, a one-wayvalved air admission passage into said by-pass duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed atthe end adjacent the crank case, a connecting rod between said piston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting into the cylinder, and a compression sealing ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston defining'between them an explosion chamber,

6. In a two-cycle internal combustion engine,

.a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder havinga fuel inlet port to the working chamber and a by-pass duct between the crank case and said port, said cylinder having an exhaust port, a oneway-valved air admission passage into said bypass duct, a piston within said cylinder havinga sleeve open at its outer or remote end and closed at the end adjacent the crank case, a connecting rod between saidpiston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting into the cylinder, and a compression sealing ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston defining between them an explosion chamber, said cylinder head having a dome within its cup portion and containing a compression space and having a spark plug receiving portion, a spark plug mounted in said receiving portion and communicating with said compression space.

7. In a two-cycle internal combustion engine, a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having a fuel inlet port to the working chamber and a by-pass duct between the crank case and said port, said cylinder having an exhaust port, a oneway-valved air admission passage into said bypass duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adjacent the crank case, a connecting rod between said piston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting into the cylinder, and a compression sealing ring for sealing the cylinder head and piston against escape of gases'there between, said cylinder head and said piston defining between them an explosion chamber, said cylinder head having a dome within its cup portion and containing a compression space and having a spark plug receiving portion, a spark plug mounted in said receiving portion and communicating with said compression space, said piston having a dome to enter the first mentioned dome during the final portion of the charge-com pressing stroke of the piston to compress the explosive mixture into the compression space.

8. In a two-cycle internal combustion engine,

a\.crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having a fuel inlet port to the working chamber and a by-pass duct between the crank case and said port, said cylinder having an exhaust port, a oneway-valved air admission passage into said bypass duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adjacent the crank case, a. connecting rod between said piston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cupsleeve projecting into the cylinder, and a compression sealing ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston defining between them an explosion chamber, said cylinder having horizontally disposed cooling flns on its outer wall and being itself inclined to the horizontal.

9. ma two-cycle internal combustion engine, a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank port, said cylinder having an exhaust port, a oneway-valved air admission passage into said by pass duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adjacent the crank case, a connecting rod between said piston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting into the cylinder, and a compression sealing ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston defining between them an explosion chamber, said cylinder head having a dome within its cup portion and containing a compression space and having a spark plug receiving portion, a spark plug mounted in said receiving portion and communiall.

a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having a fuel inlet port to the working chamber and a by-pass duct between the crank case and said port, said cylinder having an exhaust port, a oneway-valved air admission passage into said bypass duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adiacent the crank case, a connecting rod bet een said piston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust'port registering respectively with said fuel inlet port-and said cylinders exhaust port when said piston is adjacent the'crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting into the cylinder, and a compression sealing ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston defining between them an explosion chamber, said cylinderhead having a dome within its cup portion and containing a compression space and having a spark plug receiving portion, mounted in said receiving portion and communieating with said compression space, said piston having a dome to enter the during the final portion of mg stroke of the piston( to compress the explosive mixture into the compression space, said cylinder having horizontally disposed cooling fins on its outer wall and being itself inclined to the horizontal. a

11. In a two-cycle internal combustion engine, a crank case, a crank shaft mounted within the crankcase, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank a fuel inlet port to the working chamber and a by-pass duct between the crank case and said port, said cylinder having an exhaust port, a oneway-valved air admission passage into said bypass duct; a piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adjacent the crank case, a connecting rod between said piston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting compression sealing ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston defining between them an explosion chamber, said cylinder-head having cooling fins within its 'cup and over its outer end.

12. In a two-cycle internal combustion engine, a crank case, a. crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having a fuel inlet port to the working chamber and a bythe charge-compresspass duct between the crank case and. said port,

said cylinder having an exhaust port, a one-wayvalved air admission passage into said by-pass -duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adjacent the crank case, a connecting rod between said piston and said crank shaft, said cylinder having an exhaust port and said port, said cylinder a spark plug way-valved first mentioned dome cent the crankcase,

case, said cylinder 'having ing stroke of the into the cylinder, and a at the end adjacent compression sealing piston having an inlet port and an exhaust M registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and'having s a cup-sleeve projecting into the cylinder, and a compression sealing ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston 1 fining between them an explosion chamber, said 10 cylinder head having a dome within its cup portion and containing a compression space and having a spark plug receiving portion, a spark plug mounted in said receiving portion and communicating with said compression space, said cylinder head having cooling fins within its cup and over its outer end. a j 13. In a two-cycle internal combustion engine, a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having .7 i a fuel inlet port to the working chamber and a by-pass duct between the crank case and said having an exhaust port, a'one-v air admission passage into said bypass duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adjacent the crank case, a connecting rod between said piston and said crank shaft, said cylinder having an exhaust port andsaid piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjaa cylinder head secured tor-.5 the outer endof said cylinder and having acupsleeve projecting into thefcylinder, and a coni pression sealing for'sealing the cylinder head and piston against escape of gases there between,-

said cylinder'head and said piston defining be-Q 40 tween them anexpiosion chamber, said cylinder. head having a dome within its cup portion and containing a compressionspace and havin a spark plug receiving portion, a spark plug mounted in said receiving portion and communicating with said compression space, said piston having a dome to enter the first mentioned dome during the final portion of the charge-compresspiston to compress the explosive mixture into the compression space, said cylinder head having cooling fins within its cup and over its outer end.

14, In a two-cycle internal combustion engine, f a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having. a fuel inlet port to the working chamber and a by-pass duct between'the crank case and said port, sai'd cylinder having an exhaust port. a one-way-valved air admission passage into said by-pass duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed the crank case, a connecting rod between said piston and said crank shaft, said cylinder having an exhaust port and said 7 piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting into the cylinder, and a ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston .de. '75

fining between them an explosion chamber, said cylinder having horizontally disposed cooling fins on its outer wall and being itself inclined to the horizontal, said cylinder head having cooling fins within its cup and over its outer end.

15. In a two-cycle internal combustion engine, a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having a fuel inlet port to the working chamber and a by-pass duct between the crank case and said port, said cylinder having an exhaust port, a one-way-valved air admission passage into said by-pass duct, a piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adjacent the crank case, a connecting rod between :aid piston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinders exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting into the cylinder, and a compres:ion sealing ring for sealing the cylinder head and piston against escape of gases therebetween, said cylinder head and said piston defining between them an explosion chamber, said cylinder head having a dome within its cup portion and containing a compression space and having a spark plug receiving portion, a spark plug mounted in said receiving portion and communicating with said compression space, said cylinder having horizontally disposed cooling fins on its outer wall and being itself inclined to the horizontal, said cylinder head having cooling fins within its cup and over its outer end.

16. In a two-cycle internal combustion engine,

a crank case, a crank shaft mounted within the crank case, a cylinder projecting from the crank case, a one-way-valved fuel admission duct delivering into the crank case, said cylinder having a fuel inlet port to the working chamber and a by-pass duct between the crank case and said port, said cylinder having an exhaust port, a one-way-valved air admission passage into said by-pass duct, 9. piston within said cylinder having a sleeve open at its outer or remote end and closed at the end adjacent the crank case, a connecting rod between said piston and said crank shaft, said cylinder having an exhaust port and said piston having an inlet port and an exhaust port registering respectively with said fuel inlet port and said cylinder's exhaust port when said piston is adjacent the crank case, a cylinder head secured to the outer end of said cylinder and having a cup-sleeve projecting into the cylinder, and a compression sealing ring for sealing the cylinder head and piston against escape of gases there between, said cylinder head and said piston defining between them an explosion chamber, said cylinder head having a dome within its cup portion and containing a compression space and having a spark plug receiving portion, a spark plug mounted in said receiving portion and communicating with said comprezsion space, said itself inclined to .the horizontal, said cylinder head having cooling fins within its cup and over its outer end.

CLAYTON E. FREDERICKSON. 

